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test2/source/blender/draw/intern/shaders/draw_model_lib.glsl
2024-11-14 23:15:06 +01:00

130 lines
3.3 KiB
GLSL

/* SPDX-FileCopyrightText: 2018-2023 Blender Authors
*
* SPDX-License-Identifier: GPL-2.0-or-later */
#pragma once
#include "draw_view_info.hh"
#include "draw_view_lib.glsl"
#if !defined(DRAW_MODELMAT_CREATE_INFO) && !defined(GLSL_CPP_STUBS)
# error Missing draw_modelmat additional create info on shader create info
#endif
#if defined(UNIFORM_RESOURCE_ID)
/* TODO(fclem): Legacy API. To remove. */
# define resource_id drw_ResourceID
# define DRW_RESOURCE_ID_VARYING_SET
#elif defined(GPU_VERTEX_SHADER)
VERTEX_SHADER_CREATE_INFO(draw_resource_id_varying)
# if defined(UNIFORM_RESOURCE_ID_NEW)
# define resource_id (drw_ResourceID >> DRW_VIEW_SHIFT)
# else
# define resource_id gpu_InstanceIndex
# endif
# define DRW_RESOURCE_ID_VARYING_SET drw_ResourceID_iface.resource_index = resource_id;
#elif defined(GPU_GEOMETRY_SHADER)
# define resource_id drw_ResourceID_iface_in[0].resource_index
#elif defined(GPU_FRAGMENT_SHADER)
FRAGMENT_SHADER_CREATE_INFO(draw_resource_id_varying)
# define resource_id drw_ResourceID_iface.resource_index
#elif defined(GPU_LIBRARY_SHADER)
SHADER_LIBRARY_CREATE_INFO(draw_resource_id_varying)
# define resource_id drw_ResourceID_iface.resource_index
#endif
mat4x4 drw_modelmat()
{
return drw_matrix_buf[resource_id].model;
}
mat4x4 drw_modelinv()
{
return drw_matrix_buf[resource_id].model_inverse;
}
/**
* Usually Normal matrix is `transpose(inverse(ViewMatrix * ModelMatrix))`.
*
* But since it is slow to multiply matrices we decompose it. Decomposing
* inversion and transposition both invert the product order leaving us with
* the same original order:
* transpose(ViewMatrixInverse) * transpose(ModelMatrixInverse)
*
* Knowing that the view matrix is orthogonal, the transpose is also the inverse.
* NOTE: This is only valid because we are only using the mat3 of the ViewMatrixInverse.
* ViewMatrix * transpose(ModelMatrixInverse)
*/
mat3x3 drw_normat()
{
return transpose(to_float3x3(drw_modelinv()));
}
mat3x3 drw_norinv()
{
return transpose(to_float3x3(drw_modelmat()));
}
/* -------------------------------------------------------------------- */
/** \name Transform Normal
*
* Space conversion helpers for normal vectors.
* \{ */
vec3 drw_normal_object_to_world(vec3 lN)
{
return (drw_normat() * lN);
}
vec3 drw_normal_world_to_object(vec3 N)
{
return (drw_norinv() * N);
}
vec3 drw_normal_object_to_view(vec3 lN)
{
return (to_float3x3(drw_view.viewmat) * (drw_normat() * lN));
}
vec3 drw_normal_view_to_object(vec3 vN)
{
return (drw_norinv() * (to_float3x3(drw_view.viewinv) * vN));
}
/** \} */
/* -------------------------------------------------------------------- */
/** \name Transform Normal
*
* Space conversion helpers for points (coordinates).
* \{ */
vec3 drw_point_object_to_world(vec3 lP)
{
return (drw_modelmat() * vec4(lP, 1.0)).xyz;
}
vec3 drw_point_world_to_object(vec3 P)
{
return (drw_modelinv() * vec4(P, 1.0)).xyz;
}
vec3 drw_point_object_to_view(vec3 lP)
{
return (drw_view.viewmat * (drw_modelmat() * vec4(lP, 1.0))).xyz;
}
vec3 drw_point_view_to_object(vec3 vP)
{
return (drw_modelinv() * (drw_view.viewinv * vec4(vP, 1.0))).xyz;
}
vec4 drw_point_object_to_homogenous(vec3 lP)
{
return (drw_view.winmat * (drw_view.viewmat * (drw_modelmat() * vec4(lP, 1.0))));
}
vec3 drw_point_object_to_ndc(vec3 lP)
{
return drw_perspective_divide(drw_point_object_to_homogenous(lP));
}
/** \} */